Internally the fascia transversalis is con nected to the edge of the tendon of the rectos.
Midway between the superior anterior spi nous process of the ilium and the spinous pro cess of the pubes, and at from half to three fourths of an inch above the crural arch, the spermatic process escapes from the abdomen, descending within a cylindrical prolongation of the fascia by which the process is enclosed, and which thus firms a sheath for the process. By detaching this prolongation from the fascia around the process, a circular aperture is formed in the fascia, which is the deep in guinal ring, the situation of which has been just defined. On the inside of this opening are situate the epigastric vessels, the artery, and vein or veins, the artery in the former case being next the ring, in the latter at times the outer of the two veins.
2. The fascia propria is a cellular stratum in terposed between the peritoneum and the struc tures of the abdominal walls which it lines ; it varies in thickness and condition at different parts and in different subjects ; at times it con tains adeps, at others it is purely cellular, or forms a condensed expansion ; in the iliac region it is thicker upon its posterior than its anterior wall ; on the latter it increases in as it descends towards the erural arch, being so thin towards the umbilicus that the peritoneum adheres very closely to the ten dinous expansion of the muscles; at the deep inguinal ring it is more dense, and the perito neum, the fascia transversalis, and it, are more intimately connected than at either side; ex ternal to the ring, between it and the spinous process of the ilium, it is so free that the pe ritoneum may be separated without difficulty from the interior of the fascia transversalis, and along the crural arch it forms, from the external iliac artery outward, a soft mass, sometimes thick, occupying the interval left between the peritoneum and the fascia trans versalis, at the reflection of the former from the iliac fossa to the anterior wall : upon this wall it encloses the epigastric vessels, the um bilical ligament, and the spermatic vessels, and not only does it extend universally over the in terior of the abdominal walls but it is prolonged through their several apertures upon the parts which pass through them, as in the case of the spermatic vessels.
From the anterior wall of this region it passes to the posterior, where it lines the iliac fossa, and connects the peritoneum or the viscera to the iliac fascia ; at the outer part of the fossa it is remarkably free, soft, and easily lacerated, so that the peritoneum can be detached, pro bably with greater facility at this than at any other situation; at its inner part it is even more abundant, thicker the nearer to the crural arch, forming the investment by which the iliac ves sels are inclosed, and descending thence into the pelvis.
• Lastly, the peritoneum of the anterior wall is continuous inferiorly with that of the iliac fossa, being reflected from the one to the other at the distance of five or six lines above the aural arch—a fact deserving of much attention, since it permits the external iliac artery to be secured without disturbing the membrane. In its reflection from one wall of the region to the other it leaves immediately above the cruml arch, between itself, the fascia transversalis, and the fascia iliaca, a triangular interval of some lines, occupied by the fascia propria, and at times at least by one or more lymphatic glands; this space is widest at the iliac artery and diminishes as it extends outward; this fact also deserves attention, inasmuch as it points out where the fascia transversalis may be di vided, if necessary, in the operation of expo sing the external iliac with least danger to the peritoneum, viz. on the outside of the deep inguinal ring and close as possible to the crural arch. The peritoneum of the anterior wall of the fossa is weaker toward the middle line than externally; it presents toward the abdo men two depressions or recesses denominated by Velpeau " fossettes inguinales," internal and external; these depressions vary very much in their depth, sometimes hardly perceptible, at others of considerable depth and capacity, more especially the external, which is much the larger; they are produced by the projection of the umbilical ligament from the interior of the abdominal wall, and the reflection of the peritoneum round the ligament, by means of which a triangular fold, wide in proportion to the degree to which the ligament projects, is formed, the base of which is below, the apex above toward the umbilicus, and in the free edge of which the ligament is contained ; this fold separates the depressions, one being external to it, the other internal, between it and the urachus ; the external one, the bottom of which tends forward and inward, corresponds to some point of the posterior wall of the in guinal canal, but its precise relation to it is uncertain, because of the irregularity of the position of the umbilical ligament ; at times it is identical with another slight depression situate on the outside of the epigastric vessels, which marks the situation of the deep inguinal ring, the ligament in such case being behind these vessels ; at others it corresponds to the wall of the canal, to the superficial inguinal or the deep femoral rings, the ligament being in these latter eases internal to the epigastric vessels.